private Token ExtractStringToken()
{
int line = source.LineNumber;
int pos = source.Position;
StringBuilder lexeme = new StringBuilder();
StringBuilder value = new StringBuilder();
char current = source.GetNextChar(); // consume initial quote
lexeme.Append('\'');
// deal with string characters
do
{
// replace any whitespace character with a blank
if (Char.IsWhiteSpace(current))
{
current = ' ';
}
if (current != '\'' && current != Source.END_OF_FILE)
{
lexeme.Append(current);
value.Append(current);
current = source.GetNextChar(); // again consume
}
// quote ? each pair of adjacent quotes represent a single quote.
if (current == '\'')
{
while (current == '\'' && source.PeekNextChar() == '\'')
{
lexeme.Append("''");
value.Append('\'');
current = source.GetNextChar();
current = source.GetNextChar(); // consume both quotes
}
}
} while(current != '\'' && current != Source.END_OF_FILE);
TokenBuilder builder = new TokenBuilder();
if (current == '\'')
{
source.GetNextChar(); // consume final quote
lexeme.Append('\'');
builder.CreateTokenWithType(TokenType.STRING).WithValue(value.ToString()).WithLexeme(lexeme.ToString());
} else
{
builder.CreateTokenWithType(TokenType.ERROR).WithValue(ErrorCode.UNEXPECTED_EOF);
}
return builder.AtPosition(pos).AtLine(line).Build();
}
